Convectors

ABSTRACT

A convector for cooling a microprocessor includes a volute-shaped housing, a stator, and a rotor, and can be mounted to a CPU board of a computing device for thermal coupling with the microprocessor. The volute-shaped housing of the convector encapsulates the stator and the rotor, and has a radially outer casing which defines a single exit port for guiding a fluid out of the housing. The stator has a plurality of plates configured to conduct heat. The rotor has a plurality of disks and a shaft extending longitudinally along the housing. Together, the housing, the stator, and the rotor define a spiral flow path through the volute-shaped housing, in both radially outward and longitudinal directions, to the single exit port. A motor may be provided to impart rotational motion to the rotor.

REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority to U.S.patent application Ser. No. 15/238,678, filed on Aug. 16, 2016 andtitled CONVECTORS, which claims priority to U.S. Provisional PatentApplication No. 62/205,883, filed on Aug. 17, 2015 and titledCONVECTORS. U.S. patent application Ser. No. 15/238,678 and U.S.Provisional Patent Application No. 62/205,883 are hereby incorporated byreference herein in their entireties.

BACKGROUND

Convectors can be described as fluid-propulsing devices where the heattransfer occurs due to the utilization of an array of discs (rotor)interlaced with arrays of static plates (stator). The heat transferbetween the static plates and the cooling fluid takes place due to thedisruption of the boundary layer by the rotating discs on the staticplates and the movement of the fluid in and out of the device occurringdue to the resistance or drag that takes place between the discs and thefluid and the walls of the rotating discs that conform the rotor and thewalls of the static plates that conform the stator.

Bladeless blowers and bladeless turbines or blowers refer to deviceswere the fluid scooping mechanism (vanes, buckets, etc.) have beenreplaced with arrays of flat discs to produce motive forces whenutilized in conjunction of water, air or steam. Bladeless turbines wereoriginally invented in Europe were the first patent was granted in 1832,but their development continued on and by the early 1900s, manyimprovements had been made. Most notably was the device that NikolaTesla patented as a Fluid Propulsing (device). His U.S. Pat. No.1,061,142 (Filed on 1909) describes a blower or pump that, driven by amotor as shown in FIG. 1, was capable to move a fluid by using an arrayof periodically spaced discs keyed to a solid shaft. Tesla's explanationwas that the rotating discs dragged the fluid due to “lateral” or “skinresistance.” A few years later, Nikola Tesla (U.S. Pat. No. 1,061,206,Filed Jan. 17, 1911), Jonas Albert Johnsen (U.S. Pat. No. 1,056,338,Filed Nov. 1, 1911) and William A. Scott (U.S. Pat. No. 1,047,898, FiledDec. 17, 1912) patented separately their own versions of bladelessturbines.

Early designs of fan-blowers, such as the ones from Garduer C. Hawkins(U.S. Pat. No. 148,951 Filed on 1874), Kinney et al (U.S. Pat. No.157,453 Filed 1874) and Albert J. Klinginsmith (U.S. Pat. No. 182,833Filed 1876), were provided with axial openings for the air to enter thedevice. In time, new designs like the one proposed by N. B. Wales Jr.(U.S. Pat. No. 2,632,598 Filed on 1950) eliminated the intake openingson the side were the motor was to be located and air was allowed toenter only on the opposite side. Frank A. Manfredi also proposed atubular shaft in his U.S. Pat. No. 3,989,101 (Filed on 1975), but heused it as a fluid conducting conduit, for heat exchanging purposes. In2004 David Christopher Aviña filed for a patent for a “Combined CycleBoundary Layer turbine” for which he obtained U.S. Pat. No. 7,241,106.Aviña describes his device, shown in FIG. 2, as a rotating perforatedtubular conduit that allows fluid to flow between the discs.

A cylinder, made up of a combination of rotating flat discs and fixedfins behaving as an active heat sink was introduced by John Bimshas Jr.et al (all from IBM), in their U.S. Pat. No. 3,844,341 Filed on 1972.Bimshas Jr. et al's patent introduced also a variant that consisted onthe use of concentric, vertical, periodic, annular walls rotatingbetween similar, fixed structures, as shown in FIG. 3. The device,according to Bimshas et al, was intended to thermally control a devicesuch as an “intergimbal assembly of inertial guidance structures.”Bimshas Jr. et al's devices were intended to behave as radiators sincethere were no inlets or outlets provided for a moving fluid. In fact,they were designed to be fully enclosed and the gaps between therotating structures and the fixed walls were to be filled with helium tohelp reduce the thermal impedance.

By 1993, George C. Maling Jr. and Roger R. Schmidt filed for a patent ona device that they described as a “Disk augmented heat transfer system.”U.S. Pat. No. 5,335,143 was granted to them in 1994, and in it, thepatent depicts the device as a series of equally spaced, parallel discs,attached to a rotatable shaft, as shown in FIG. 4. The discs were placedbetween fins of a heat sink, once in motion the discs removed the heatfrom the fins by the disruption of the thermal boundary layer (on thefins).

Twenty five years later, another group of investigators and scientistsworking also for IBM, took Bimshas et al's design and modified it. LeoH. Webster Jr. et al filed for a patent in 1997 getting one granted bythe middle of 1998 (U.S. Pat. No. 5,794,687). The device was given theself-explanatory name of “Forced Air Cooling Apparatus for SemiconductorChips” and, unlike Bimshas et al's device, it consisted of severalhorizontal discs contained within a cylindrical heat sink with intakeand exhaust ports located along the perimeter of the cylindricalstructure, as shown in FIG. 5.

Kinetic cooling consists of a spinning disc or, in some cases, aspinning impeller that hydroplanes over a hot area just a few micronsaway. In a counter-intuitive process, heat transfer in these devicestakes place conductively through the minute air gap between the hotsurface and the rotating surface of the disc or impeller. The heat,transferred to the disc, is then carried away by the air going over thetop surface of the rotating disc or through the vanes of the spinningimpeller. Recent patents and patent applications related to thistechnology include Jeffrey P. Koplow U.S. Pat. No. 8,988,881 (Filed on2010) and U.S. Pat. No. 8,228,675 (Filed on 2010). In his designs,Koplow has incorporated a spinning, heat sink with swept vanes over avapor chamber acting as a heat spreader, as shown in FIG. 6. Similarly,Daniel Thomas Pat. App. No. 20120227940 (Filed on 2011) describes asmall toroidal fluid mover that hovers above a credit-card size heatspreader that is partially filled with a fluid, as shown in FIG. 7.Finally, Lino A. Gonzalez Pat. App. No. 20130327505 (Filed on 2013) hasa device very similar to Koplow's but with improvements to maintain thespatial gap constant, as shown in FIG. 8.

The technical background leading to the invention of these novel devicesreferred as convectors can be explained through the seminal work of W.Odell, Ludwig Prandtl, Heinrich Blasius, Alec E. Beason and Theodore vonKármán along the various technical improvements, devices and methodspreviously mentioned.

In Jan. 23, 1904 W. Odell published his findings related to air frictionin the Electrical Review^([1]), a UK based, weekly-magazine dedicated toinforming the electrical industry about power generation, powerdistribution, factory automation, renewable energy, building servicesand power quality. The article, entitled “Preliminary Experiments on AirFriction,” presented his findings related to the “loss of power due tofriction with the air of large rotating objects . . . ” Odell ran aseries of experiments with discs of various discs. In his experimentsOdell was well aware of the behavior of the air on a rotating disc,describing the effect with the help of a simple sketch he said “Let AB,FIG. 4, be the edge view of a disc of radius rat its centre parallel toCD and delivering it radially at A and B to travel along the pathindicated by the arrows, and to return ultimately to the centre again.”Utilizing the formula for the loss of energy of a fluid through a pipe,conjuring up the law for centrifugal pumps and manipulating the resultsfrom his experiments, Odell arrives to the rate of the loss ofenergy=Cω²r² hoping to determine the value of the coefficient C infuture experiments. In the same year, on August 1904, Ludwig Prandtlpresented at the Third International Mathematical Congress inHeidelberg, Germany, a paper where he introduced the concept of theboundary layer^([2]). According to Prandtl, a fluid slows down only in athin layer next to the surface that is moving over. This thin layer, aboundary layer, starts forming at the beginning of the flow and slowlyincreases in thickness. It is laminar in the beginning but becomesturbulent after a point determined by the Reynolds number. Since theeffect of viscosity is confined to the boundary layer, the fluid awayfrom the boundary may be treated as ideal. The fundamental conceptsuggested by Prandtl, defines the boundary layer as a thin film of fluidflowing with very high Reynolds Numbers (Re), that is, with relativelylow viscosity as compared with inertia forces. Because computation ofthe boundary layer parameters is based on the solution of equationsobtained from the Navier-Stokes equations for viscous fluid motion, theintroduction of the concept of a very thin boundary layer provided aconsiderably simplified solution to these equations. It should be notedthat, in spite of its relative thinness, the boundary layer is veryimportant for initiating processes of dynamic interaction between theflow and the body. The boundary layer determines the aerodynamic dragand lift of the flying vehicle, or the energy loss for fluid flow inchannels.

Prandtl's work was followed by that of his student Heinrich Blasius,whom in 1908 published in the respected journal Zeitschrift furMathematik and Physik, his paper “Boundary Layers in Fluids with LittleFriction,” ^([3]) discussed 2D boundary-layer flows over a flat plateand a circular cylinder. Blasius went to solve the boundary-layerequations in both cases, providing an even more accurate solution forthe skin-friction drag than the one offered in Prandtl's paper.

Over a decade later, on August 1919, an electric engineer, Alec BirksEason, publishes in London, a book entitled “Flow and Measurement of Airand Gases.” ^([4]) The book consisted of a series of chapters thatprovided information related to air and gas flow. In the book, in achapter entitled “Friction on discs,” Eason discusses the work of W.Odell related to the experiments on the power required to rotate discsin air. In 1904, Odell's article indicated that “for a fixed speed ω,but variable diameter d, torque varied as (d)⁵⁻⁶” and that “the loss ofkinetic energy in friction per unit weight of air depended on the lengthof the path which the air had to travel.” Eason claimed that he coulddeal with the disc friction in another way. He indicated: “a disc movingat some velocity in still air will experience a retarding force k, wherek will depend upon whether the surface has other surfaces near it ornot, and will vary with the existence of other surfaces near therotating disc, so that two discs near together should experience moreresistance to motion than the same two discs placed far apart, becauseeach disc sets up its own eddies, and the two sets of eddies resist eachother.” After defining a formula for force, torque and power he added:

“If a series of discs were placed on a shaft and the whole series wererotated, and if fixed discs were placed between each of the rotatingones, by altering the number of the discs we should get a good measureof the friction and should be able to find the value of k. If thisarrangement is air-tight, so that the pressure of the air in which thevanes rotate can be varied, we could get the value of k for variouspressures: it should vary nearly as the pressure.”

The simplest kind of rotating disk system is the “free disk,” aninfinite-radius rotating disk in a fluid. This was originally examinedby Theodore von Kármán^([5]), a former student of Prandtl's and aprofessor at the University of Aachen, whom in 1921, obtained amomentum-integral equation through the simple process of integrating theboundary-layer equations across the boundary layer showing that, thedisk drags fluid from the rotor center to the outside edge, at the sametime, drawing fresh fluid inward axially. As a result of Kármán's workthe boundary layer theory finally began to receive more attention andacceptance in the technical community. Prandt'l boundary-layer ideaprovided a revolutionary way to conceptualize fluid dynamics and helpedremove the confusion related to the role of viscosity in a fluid flow.After Prandtl, the fluid dynamicist could quantitatively calculate theskin-friction drag, that is, the drag due to friction on a surfaceimmersed in a fluid flow.

REFERENCES

-   1. W. Odell, “Preliminary Experiments on Air Friction” Vol. CLIV No.    4 Electrical Review, New York, Saturday, Jan. 23, 1904-   2. John D. Anderson Jr., “Ludwig Prandtl's Boundary Layer”, December    2005, Physics Today, pp 42-48-   3. P. R. H. Blasius, Z. Math. Phys. 1 (1908)-   4. Alec Birks Eason, “Flow and Measurement of Air and Gases”,    Philadelphia: J. B. Lippincott Company, August 1919. Chapter XII,    Air Friction on Moving Surfaces, C—Friction on Discs, pp 224-227-   5. T. von Kármán, “Über laminare and turbulente Reibung,” Z. Angew.    Math. Mech., vol. 1, no. 4, pp. 233-235, 1921.

SUMMARY OF THE INVENTION

Convectors can be described as a combination of fluid propulsing deviceswith integrated forced convecting mechanisms. Designed to behave likeblowers or pumps, convectors rely on the disruption of the boundarylayer in order to promote heat exchange.

Simple in construction, a convector consists of a stator made up of anarray of fixed, parallel, equally spaced, equally thick, thermallyconductive plates attached to a relatively thick thermally conductiveplate. Convectors are provided with a rotor that is made up of an arrayof flat, rotatable, parallel, equally spaced, equally thick discs. Thediscs of the rotor are placed between the plates of the stator atrelatively close proximity from the walls of the stator plates.Furthermore, the discs are keyed or held in place with the help ofspacers and compression nuts to a hollow or a solid shaft. To allow thefree rotation of the shaft, a clearance aperture, circular in shape, isprovided on the stator plates. In addition, the shaft is held in placeat both ends by roller bearings that provide the means for the shaft torotate. Convectors running with non-compressible fluids require sealsthat are also added to the end of the shafts. To impart rotationalmotion to the rotor, the shaft is attached to an external device such asa motor.

Convectors can be designed to have either perforated hollow shafts orsolid shafts. In the case were the device is fitted with a hollow shaft,the shaft serve as a conduit for the fluid to ingress or egress thespace between the static plates, the rotating discs and the deviceitself. Alternatively, convectors designed with solid shafts, requirethe addition of air passages on the static plates, rotatable discs, andthe lateral walls of the external housing. Regardless of whether theshaft is hollow or solid, convectors are also provided with a mainexhaust port, nests for bearings, bearings, seals and a casing or shell.To contain the fluid within the device, while the fluid moves across allthe surfaces of the stator, a scroll-shaped (a) casing is designedaround each disc. This feature is obtained by the addition of finspacers that allow each disc to rotate within its own cylindrical spacewhile eliminating unwanted spaces and helping push the fluid out. Finsand walls designed with bosses and indentations to create thescroll-shaped (a) casing provide an alternate option. The main exhaustport in convectors is the result of combining many, individual discexhausts into one. Because the exhaust is tangential to the perimeter ofthe discs, the exhaust is usually designed to direct the fluids upwardor laterally away from the unit, although if convenient, the exhaust canbe expelled downwards. Lateral walls, axially perpendicular to theshaft, are designed to have nesting features for bearings that will beutilized in conjunction with the shaft. All convectors are designed tobe utilized with compressible and non-compressible fluids. Fornon-compressible fluids, seals are added to the end of the shaft toprevent leaks. Whether utilizing a single casing or several plates,gaskets may be required to completely seal the device and ensure thatthe fluid moving through the device exits only at the exhaust port. Inoperation, a convector's base is placed in intimate contact with the topsurface of a heat source utilizing some compressive force. Heattransfer, between the heat source and the base of the convector, isenhanced by applying a thermal compound that fills the voids and minutegaps. As heat moves into the base of the convector, it spreads acrossit. This causes the heat to travel into all of the stator plates.Rotating discs, placed at a relative close distance from the statorplates, disturb the boundary layer causing the heat to move from thestator plates to the moving fluid surrounding the plates and discs.Moving in an outward radially-spiral motion, the heated fluid exits thesystem through an exhaust port.

Convectors can be utilized in many commercial, medical, military andlaboratory applications (just to name a few) where the need for aneffective mechanism of heat management is sorely needed. Examples ofapplication of convectors include cooling of high power electroniccomponents, cooling of high power resistors, cooling of illuminationLED-based devices, etc.

Convectors have a unique set of characteristics that makes them highlydesirable as active heat sinks. For example:

-   -   Convectors can be utilized to work with gases, liquids or both        mediums;    -   Convectors are fully reversible, meaning that the inlets of a        convector can be made to behave as exhausts and the exhausts as        inlets, simply by rotating the motor in reverse;    -   The performance of the heat exchanging section of a convector        does not change when running in reverse mode;    -   Because of their design, convectors will have low debris and        dust collection;    -   Convectors' can be designed to operate in a vertical orientation        (with the discs standing on their edges) or horizontally (with        the faces of the disks parallel to the surface were the device        rests) provided that a compression system for the discs and        spacers be included;    -   Convectors behave, by design, like water-pumps or like        air-blowers;    -   Convectors can be further specialized as volume-blowers,        pressure-blowers, volume pumps or pressure pumps by simply        changing the diameter of the discs or modifying the shape of the        scroll-shaped (σ) casing;    -   Convectors' performance can be further improved by modifying the        surface of the stator plates and/or the surface of the discs;    -   Convectors built with smooth discs can be expected to run        quietly;    -   Convectors can be ganged up in series, utilizing a single motor        to provide rotational motion to several devices;    -   Convectors can be utilized in conjunction with heat pipes or        with vapor chambers for effective management of hot spots on        components that need critical thermal control;    -   Because convectors behave like blowers, their performance is not        noticeable affected when the hot exhaust and/or inlet is/are        channeled to or from a preferred location utilizing extra        conduit.

Convector in Operation (Hollow Shaft)

To describe the behavior of a convector in operation, we will consideran application, where a small convector will be utilized to maintain thecase temperature of a high power electronic component (i.e. amicroprocessor) to some pre-determined temperature limit.

Convectors utilized to cool high power electronic components such asmicroprocessors can be designed with heat sink structures acting asstators. As such, convectors of this kind can be fitted with a mountingmechanism to attach the device over the electronic component in order toapply the right amount of pressure. To obtain a good thermal contact andreduce the thermal resistance between the convector and the electroniccomponent, thermal grease with high thermal conductivity should beapplied between the convector's base and the top of the electroniccomponent before finalizing the attachment of the convector.

The base and the fins of the stator should preferably be made from highthermal-conductive materials (i.e. aluminum, copper, graphite, CarbAl®,KFOAM®, etc.). The surfaces of bases of this kind of convectors requirebeing as smooth as possible and with flatness equal or better than±0.0005 inches [˜13 micrometers] to be effective when in contact withthe electronic component. The thermal grease that is added between theconvector and the electronic component is utilized to fill the void andcrannies mostly on the surface of the electronic component's case. Withthe help of good interface thermal compound (i.e. Artic Silver 5), heatwould move away from the case of the microprocessor and into the base ofthe stator, making the base to behave as a heat spreader. Fins or statorplates, made from highly conductive materials and directly attached tothe base of the stator, would move the heat quickly away from the base.Assuming that the rotor of the convector is moving at some relativelyhigh rotational speed, the rotation of the discs would make the discsdrag along the air between the surfaces of the stator fins and thesurfaces of the discs. The discs in all convectors are designed torotate at a short distance, ˜0.010-0.080 inches [˜0.25-2.00millimeters], from the surfaces of the fins or the surfaces of theplates that make up the stator and due to the resistance to move, thatall of the rotating components and air experience, the boundary layer atthe fins gets disturbed. The heat from the base that has moved into thefins would then be carried away convectively by the air that is beingpushed outwardly in a radially-spiral motion due to the centrifugalforce generated by the spinning discs. The volume of air moved away bythe spinning discs would be replenished through apertures or passagesalong the length of the shaft and at the inner edge of the discs thatrest against the shaft. Two main air intakes, located at both ends ofthe shaft would provide all of the air required to maintain a continuousflow through the convector. Because convectors are blowers (or pumps) bydesign, the warm-exhaust air would be expelled away from the convectorwith a substantial force. If needed, an exhaust pipe over the exhaustport of the convector could be utilized to send the warm-exhaust airoutside the case to prevent recirculation by the convector. It can besafely assumed that the air at close proximity of the convector would beroughly at room temperature or slightly above room temperature (i.e. 68°F. [20° C.]), and if the fins or plates of the stator were to acquire ahigher temperature (i.e. 97° F. [36° C.]) the difference in temperaturesbetween the fins and the supplied air would be large enough for aneffective forced-convective transfer to take place.

It should be noted that, unlike any currently known devices, convectorswith heat-sink-like structures are designed to make every single surfaceof the stator (in close proximity to the surfaces of discs of therotor), help distribute the heat rejected by the source into the base ofthe convector. This is done in conjunction with the rotor's discs thatare also purposely designed to remove the heat travelling through everysingle surface of the vertical walls that make up the stator and thelateral walls of the convector and because the stator is made up of manyvertical, closed-spaced, long and wide thin plates, the outcome is thatthe base experiences an even heat distribution over the entire surfaceand any potential hot spots are eliminated.

Convectors are highly versatile and their heat exchanging performancecan be modified and improved in several ways. For example, in theapplication related to controlling the temperature of an electroniccomponent, if the need for higher heat removal would've arisen, themotor could've been made to spin faster in order to increase the volumeof fresh air moving through the device; or, thicker discs could've beenutilized to reduce the gap between discs and plates in order to reducethe boundary layer; or, the smooth discs could've been replaced withdiscs with modified surfaces in order to enhance the degree ofdisturbance of the boundary layer; or, the stator could've been replacedwith an stator carrying more plates along with a rotor with more discsin order to improve the cooling capabilities of the device. One of theunique features of convectors is that they can be pre-designed to useeither air or water as a cooling medium. When a convector is designed tobe utilized along with water, seals are added at both ends of the shaftto prevent leaks and the exhaust port and fluid intakes are channeledthrough an external heat exchanger. Because convectors are pumpsper-design, there is no need to add a water pump, but because of thedifference of the densities and viscosities of the cooling medium,motors with higher power requirements are utilized.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The foregoing and other features and aspects of the invention may bebest understood with reference to the following description of certainexemplary embodiments, when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is a view of a prior art blower or pump.

FIG. 2 is a view of a prior art cycle boundary layer turbine.

FIG. 3 is a view of a prior art cylinder with rotating flat discs andfixed fins.

FIG. 4 is a view of a prior art disk augmented heat transfer system.

FIG. 5 is a view of a prior art forced air cooling apparatus forsemiconductor chips.

FIG. 6 is a view of a prior art spinning heat sink.

FIG. 7 is a view of a prior art toroidal fluid mover.

FIG. 8 is a view of another prior art spinning heat sink.

FIG. 9 is a perspective view of four basic convectors in accordance withexemplary embodiments.

FIG. 10 is an exploded illustration of the convectors shown in FIG. 9.

FIG. 11 is a perspective view of a convector embodiment with a hollowshaft.

FIG. 12 show some characteristic components of a convector embodimentshown in FIG. 11.

FIG. 13 illustrates the comparison between convector embodiments withsolid and hollow shafts.

FIG. 14 illustrates the comparison of rotors with solid shafts androtors with hollow shafts.

FIG. 15 shows a basic convector design, components and basic operationdetails.

FIG. 16 is a perspective view of a convector designed for coolingelectronic components.

FIG. 17 illustrates an exploded view of the convector shown in FIG. 16.

FIG. 18 shows an isometric view of a rotor designed with a compressionsystem.

FIG. 19 shows the comparison of a rotor with free floating discs and arotor with a compression system.

FIG. 20 depicts the frontal, top and cross-sectional views of variousdisc design embodiments.

FIG. 21 illustrates several discs with various surface configurationsand finishes.

FIG. 22 is a perspective view of a hollow shaft design versus a solidshaft design.

FIG. 23 illustrates a top view of a representative hollow shaft designand various cross-sectional geometries of hollow shaft designs.

FIG. 24 depicts various air opening designs on hollow shafts.

FIG. 25 is a perspective view of various hollow shafts presentingvariations related to the number of main air passages and shaft ends.

FIG. 26 illustrates the top view of several discs and hollow shafts, aperspective view of a single disc placed onto a hollow shaft and a closeup view for clarification of the design.

FIG. 27 presents the perspective view of various hollow shafts and across-sectional view of a hollow shaft with openings designed to imparta rotational motion to the fluid.

FIG. 28 depicts the perspective view of various solid shafts withrelative small shaft-diameter designs and respective cross-sectionalgeometries.

FIG. 29 presents the perspective view of several convectors set-up inseries for a cooling application related to high power electroniccomponents.

FIG. 30 presents the isometric view of various base designs.

FIG. 31 shows the isometric view of various flat-fin design geometries.

FIG. 32 shows the isometric view of various fins with built-instructures (bosses and indentations).

FIG. 33 shows the isometric view of a convector design based on non-flatfin structures.

FIG. 34 is an exploded view of the convector shown in FIG. 33.

FIG. 35 shows the isometric view of volume convectors and pressureconvectors.

FIG. 36 presents the cross-sectional view of two volume convectors.

FIG. 37 shows the cross-sectional view of three pressure convectors.

DETAILED DESCRIPTION OF THE INVENTION

The present invention generally relates to novel devices, methods andsystems for facilitating the convective transfer of heat by the movementof fluids utilizing a plurality of equally parallel and spaced rotatingdiscs and static plates using the disruptive boundary layer mechanism.

FIG. 9 shows four characteristic designs for novel convectors utilizedin applications related to the transfer of energy, in the form of heat,from or to a fluid utilizing a combination of interleaved flat-staticplates and flat-rotating discs, where the surfaces of the discs andplates are located at relatively close proximity from each other.Furthermore, the cross-sectional shape of these devices (referred hereand thereof as a scroll-shape (σ)), is purposely designed so that thedevices behave as fluid propulsors while simultaneously acting as energy(heat) transferring devices utilizing convective mode energy transfermostly by boundary layer disruption on the surfaces of the statorplates. The devices shown differ from each other by slight externalvariations, but much pronounced internal differences. For example, 901is a device designed to include a hollow shaft with openings at bothends. The openings serve the purpose of fluid intakes. These types ofdevices have discs that are not attached to the shaft and are able tomove freely. 902 shows a device designed with a solid shaft that alsohas freely moving discs. These types of devices require radially intakeopenings to surround the shaft on the back and frontal walls, therotating discs and the stator plates. 903 is another device that isdesigned with a solid shaft, but, unlike the devices of 902, the discsare held in place with a compression system consisting of disc spacersand compression mechanisms located at both ends of the shaft with theremaining design characteristics remaining the same. 904 presents adevice designed for non-compressible fluids and it is also designedutilizing a solid shaft with a compression system plus seals to preventthe fluid from leaking. These devices can have one or two fluid intakeports.

Regardless of the application on hand, most convectors share a largenumber of characteristic design parameters and components. FIG. 10 showssome of these common components including a frontal plate 10A, a bearingat the frontal end of the shaft 10B, a shaft 10C, circular discs 10D, acover or casing 10E, a base 10F, fins 10G, a bearing located on the backend of the shaft 10H, a back plate 10I, a coupler 10J and a motor 10K.

Simple in design, novel scroll-shaped (σ) convectors, such as the oneshown in FIG. 11, have just a few characteristic external features.These features include frontal and back fluid intakes, a top fluidexhaust, components to mount the motor against the casing of theconvector (bosses, spacers and screws), a device that providesrotational motion (motor), a mechanism to attach the motor to the shaft(coupler), a flat base and in most cases a scroll-shaped casing. Theassembly (FIG. 12) of the convector includes a frontal plate 12C,provided with a nesting feature 12A to hold and retain a bearing 12D andan opening 12B to clear the end of a shaft 12H. An array of flat discs12G are provided with an opening 12F, such as the one shown on disc 12E,allows the discs to be inserted onto a shaft 12H. The discs 12G areplaced between fixed, static plates 12I that are in intimate-thermalcontact with a base 12K. A circular opening 12J is provided on all ofthe static plates to allow the shaft 12H to rotate freely. To providestability to the static plates, extra holding bars are provided as shownin the close view 12L. A motor 12O, held in place with screws andspacers 12Q is attached to the shaft with the help of a coupler 12P. Ascroll-shaped casing 12M is provided with an exhaust port 12N to let theexhaust fluid escape the device.

Convectors design versatility allows the use of hollow shafts or solidshafts. FIG. 13 shows the main fluid intakes on a design that includes ahollow shaft. In designs such as these, the main fluid intakes arelocated at both ends of the shaft 13A with a fluid passage that coversthe entire length of the shaft 13B and that includes multiple fluidpassages 13C, so that the fluid entering the device gets distributedbetween the fins and the rotating discs. In contrast, a convectordesigned with a solid shaft is provided with fluid intake openingslocated at both the frontal and back walls of the device 13D. Theseopenings are also provided on all of the components within the devicesuch as the discs 13F and the static plates 13G making a continuous setof fluid passages that run the length of the device 13E. Althoughconvectors do not have a rotor per se, the overall assembly of discs andshaft within the device makes them behave rotor-like.

FIG. 14 compares rotors made with solid shafts 14B and hollow shafts14H. Both assemblies consist of an array of flat-parallel discs equallyspaced 14A and 14G. Rotors with solid shafts have flat-circular discs14C that are provided with several openings 14D surrounding a centralhole intended to clear the rotating shaft. The openings on the discs areintended to create several continuous fluid passages 14F. Rotorsdesigned with hollow shafts 14H get populated with flat-parallel,equally spaced discs 14I that have a single central opening intended forthe shaft 14H. Hollow shafts are intended as conduits for the fluid thatenters the device. The fluid enters the device via two sets of fluidintakes located at both ends of the shaft 14K, and moves within theshaft through a central passage 14J. The fluid is dispersed between thediscs (and plates) with the help of many fluid openings 14L located onthe sides along the length of the shaft.

A typical convector (see FIG. 15) is designed to have a multiple numberof flat-parallel discs 15A and a multiple number of flat plates 15B thatare interleaved 15C in a manner such that the surfaces of the discs andthe surfaces of the static plates will end up at relative closedistances. With the help of a shaft 15D, bearings 15E and an externalmotor 15F the discs can be rotated concurrently 15J. The resistance tomove, experienced by the fluid against the surfaces of the discs andstatic plates, causes the fluid to move and to be pushed out of thedevice that is completely contained with a casing 15G. The fluid 15Lexits the device via an exhaust port 15K and end openings 15H providedon the lateral walls, discs and plates 15H create a passage for freshfluid 15I to enter the device and to move between the discs and plates.

Convectors can be designed for applications related to the temperaturecontrol of high power electronic components such as microprocessors incomputers or amplifiers in power sources. A device designed for use witha microprocessor is depicted in FIG. 16, where a mounting mechanism isprovided to ease the installation of the device. Just like mostconvectors, the device (referring to FIG. 17) has a motor 171 that canbe attached to a frontal wall 175 on bosses where threaded holes areprovided 174. Screws 172 can be utilized to mount the motor against thewall. Spacers 173 and a coupler 175 help align the motor with the shaftof the convector 17A. A bearing 179 is press-fitted into a nestinglocation 170 on the frontal wall 175. An opening on the nesting location170, allows the shaft to expose its end to meet with the end of themotor's shaft. A base 17F made from highly conductive metal is populatedwith flat plates or fins 17E, into equally spaced grooves 17G machinedon the top surface of the base. The device shown here is designed with asolid shaft and with a single air pipe 17M located on the back wall 17J.The pipe directs the incoming air to a series of radial openings 17K,located at some distance from the central point where the shaft 17Arevolves. Radial air openings 178 are provided also on the discs 177 andfins 17E. The discs 177 are designed to have a central opening 17C werethe shaft 17A can slide freely. Fins are also provided with a circularclearance opening 17H intended to allow the shaft to rotate withouttouching the fin's walls. Because the fins 17E are wide at the pointwhere they get attached to the base, fin separators 17D with a circularshape on the inner wall facing the discs, are added to the assembly.This design includes also a retaining bar 17X to prevent the fins frommoving and disc spacers 17Z to keep the discs 177 at the right distancefrom the fins 17E. A bearing at the back side of the shaft 1W is alsopress-fitted into a cavity or nest 17L located on the back wall 17J. Thebase 17F, fin separators 17D, fins 17E, holding mechanism 17P, screws17Q, captive screws 17R, springs 17S and retainers 17T are pre-assembledbefore the discs 177 and disc separators 17B get placed in between thefins. Once this operation is completed, the shaft 17A is placed throughall of the discs 177 and disc separators 17B and the front wall 175 withbearing 179 attached, is placed over the shaft 17A. In a similarprocedure, the back wall 17J with respective bearing 17W is placed overthe other end of the shaft. At this point, the retaining bar 17X isplaced over the top of the fins 17E and the casing 17N, with a built-inexhaust port 17V, is placed over the complete fin-disc assembly. Afterthe casing and walls are fully secured with fasteners (not shown), themotor 171 is attached to the end of the shaft with the use of a coupler176. Screws 172 and spacers 173 help attach the motor to the front wall175 to finish assembling the device.

Some convectors are designed with rotor assemblies that require acompression mechanism; FIG. 18 shows a rotor where a solid shaft 18B ispopulated with flat, circular, equally thick, equally-spaced discs 18A.The assembly includes disc spacers 18C, end seals 18D with O-rings 18Eand a compression structure 18G fitted with set screws 18H. The shaftdesign 18B includes a threaded section for the compression mechanism 18Gand smooth, cylindrical surfaces at both ends to allow the bearings thatwill be mounted at its ends to rotate with minimum effort. The end ofthe shaft where the motor gets attached can be provided with a flatsection to ease the mounting procedure.

Depending upon the application, convectors can be designed with solidshafts coupled to free-floating discs or with solid shafts where thediscs have to have a compression system. FIG. 19 shows two rotorassemblies to show the main differences between these two options. Therotor on the top left is of the kind where a compression mechanism isincluded 191, along with end-seals 192 and nesting O-rings 195. Thecompression structures 191 are threaded on the shaft 193 and heldsecurely in place with the help of set screws 196. Disc spacers 197 andkeys 198 placed on the shaft 193, secure all of the discs 194 atpre-determined distances. The rotor at the bottom of the drawingexemplifies the free-floating disc type. These rotors are provided withdiscs 194 where a central opening allows the shaft 193 to slide freely.Because the discs float on the shaft without any impediment, this typeof rotor can only be utilized in devices oriented with the edge of thediscs perpendicular to the surface the device sits on. Devices withrotors that include a compression system can be utilized in anyorientation.

One of the main components of convectors is discs, in fact, many ofthem. Discs, circular in shape are flat and thin and they are utilizedin convectors as part of rotor assemblies and can be manufactured frommetals and non-metals alike. Placed between fins, discs (with samediameter and thickness) help in the process of heat exchanging as theyrotate creating disturbance in the boundary layer of the stator plates'surfaces. Discs do not have to be completely flat as can be seen in FIG.20. Circular discs 20A that have flat cross-sections with some specificthickness 20B are the most common design utilized in convectors. Anotherdesign approach includes flat discs 20C with a thicker section 20E inthe center of the disc. This design removes the need for disc spacersand the thicker section 20D provides better support and a strongerholding mechanism to the shaft. Yet another design on flat discs 20Fincludes a metal insert 20G placed in the middle of a non-metal disc,the insert could be made thicker than the rest of the disc 20H. Discswith metal inserts are much stronger than any of the other designs shownand if they are properly designed, they can also eliminate the use ofseparate disc spacers. Of all of the designs, discs with metal insertsare the most complicated and expensive to manufacture.

Discs are an integral component of convectors and they could be flatwith smooth surfaces or relatively flat with features on both surfaces.FIG. 21 shows a sample of the large variety of designs and surfacegeometries that discs intended for use in convectors could have. Of allof the designs, the most straight forward and simple is that of aperfectly flat disc with smooth ages and polished surfaces 21A; otherdesigns include discs with surfaces on which certain features (bosses,dimples, indentations, etc.) have been provided across the full face ofthe disc 21B, 21 i, 21K; other design variation include specificgeometric features such as vanes, grooves, dimples, bosses, indentationsor bumps set in radial, circular or spiral configurations 21C, 21D, 21E21F, 21G, 21H, 21J, 21L; yet another variation includes non-smooth edges21K. Depending upon of the desired effect expected from the discs, theaddition of features to the surfaces of discs help increase their totalsurface area. In return, the greater surface area help their performanceas aids in the heat exchanging process. If discs are utilized withnon-compressible fluids, discs may be designed to include radialfeatures to act as vanes and help stir and push the fluid.

Shafts utilized in convectors can be of the solid-bar type or thehollow-tubular type. FIG. 22 shows both of these types. Shafts made fromsolid bars 22B are simple and have just a few features. Shafts of thehollow-tubular type 22A are complex and have many more features than thesolid-bar type. Regardless of the type, shafts of both types shareseveral features, among these features, shafts have an area intended forbearings to ride on 22C, planar areas to support the discs 22D, and amechanism to attach them to a rotating device 22E. A hollow tubular typeof shaft includes extra features such as air passages located at bothends 22F, and air passages along the full length of the shaft 22G. Forobvious reasons, the complexity of hollow-tubular shafts makes themdifficult and expensive to manufacture.

Shafts of the hollow-tubular kind (FIG. 23) are designed with somedistinct features that include fluid passages at both ends 23B, an areaat the both ends to allow a bearing to be mounted 23A and fluid passagesalong the full length 23C. Shafts of this type have cross-sectiongeometries with features that help discs placed over them to get“locked” or “keyed” in place, so that if the shaft rotates, so do thediscs. Some of the cross-section designs include, but are not limitedto, round shafts 23D with bumps along the length 23E; round shafts 23Fwith grooves along the length 23G; shafts with three sides 23H; shaftswith four sides 23 i; shafts with five sides 23J; shafts with six sides23K and shafts with seven sides 23L.

Hollow-tubular shafts are designed to have, in most cases, fluidopenings at both ends and a series of fluid openings along its length tohelp distribute the fluid that enters the ends. FIG. 24 shows a top viewof a sample that includes fluid openings at both ends 24A and a varietyof shapes for the openings along the length. It should be understood,that the geometries and shapes presented, constitute only a glimpse of alarge number of possible geometries and shapes. The fluid openings canbe oval-shaped 24B, diamond-shaped 24C, rectangular-shaped 24D,round-shaped 24E, square-shaped 24F, cross-shaped 24G, consist of alarge number of small round holes 24H or have a variable set ofrectangular 24 i or round openings 24J. In any case, the openings haveto be placed at regular intervals along the length of the shaft and mostbe designed so that the shaft remains strong and capable for operationat high speeds and to help distribute the fluid between the discs thatmake up the rotor and the fins or plates that make up the stator. Shaftsof this type can be manufactured with metals and non-metals, but theneed for strength and durability makes the choice for metals a given.

Hollow-tubular shafts are always provided with, at minimum, a single,main-fluid intake (or a set of smaller openings) at one of its ends andat most, two points of attachment for a rotating device (one at each endof the shaft). FIG. 25 shows the various options available, includingshafts with two attachment features to a rotating device 25D or a singleattachment feature to a rotating device 25D. All shafts are providedwith main fluid openings at either one or both ends of it. The featurethat allows fluid enter the device may consist of a single opening or aseries of smaller openings designed at one or both ends of the shaft25A, 25B and all shafts must include a smooth area at both ends to placeand hold a bearing there 25C.

As it has been indicated in FIGS. 12, 13 and 14, there are variousapproaches and rotor assemblies that depend upon of the mechanism thatholds the discs in place. The most simple of these mechanisms requirethat the discs be designed with central openings matching the perimeterand shape of the shaft that ultimately will hold them. FIG. 26 shows forease of understanding, a single disc 26A placed over a hollow shaft 26B.There are many variations that the shaft may have, as far as its crosssection is concerned. From the sample presented 26C, the first item onthe top row, first column has been selected to show a close view of theshaft-disc relationship 26D. It can be observed, that for thecylindrical shaft with four-lobes, that the central opening on the discis slightly greater by some dimension 26E. Regardless of the shape andnumber of sides that the shaft may have, the central opening on thediscs, must allow the easy installment of the shaft.

Because fluids have the natural tendency to look for the path of leastresistance when placed in a condition where flow is compromised, hollowshafts with regularly spaced fluid passages may not work as expected.That is, fluid may not flow at the same rate at every point along thelength of the shaft. In situations like this, the fluid may come atfaster or slower rates at different points between the rotating discsand the static plates. This behavior will cause heat transfers to bedifferent at every point with a different flow rate affecting theoverall efficiency and performance of the device. Referring to FIG. 27,to avoid this behavior, shafts with single intake ports 27A can bedesigned to have regularly spaced openings with variable open area. Theopenings closer to the main fluid entry port should be designed to havea small open area and the area should be increased as the axial locationof the openings is increased too. If the shaft is provided with dualfluid entry points, the same approach utilized on single fluid entrypoint should be used, the resulting effect is that of small open areapassages near the entry ports and large openings in the middle of theshaft 27B, 27C. If turbulent flow is required, a special shaft 27D withtangential ports 27F to the inner diameter 27E can be designed. Ofcourse, the designs previously discussed represent only a few of manydesigns that can help control the flow rates of fluid entering thedevice through the shaft.

As it has been pointed before, convectors, or should it be said, rotorsfor convectors can be designed with either hollow shafts and/or solidshafts. FIG. 28 shows a sample of possible, but not limited to,configurations and geometries for several solid shafts. Solid shafts arecomponents designed to perform various tasks including holding severaldiscs, provide rotational motion to the discs and locking or keying thediscs so that they can be rotated simultaneously. Some three-dimensionaldesigns (and their cross sections) include round shafts with lobes 28A,round shafts with grooves 28B, three sided shafts 28C, square shafts28D, five sided shafts 28E and hexagonal shafts 28F. Solid shafts haveseveral advantages over other shaft designs. Some of these advantagesinclude design simplicity, small size, small weight and small cost.Solid shafts should be considered the first choice over any other choicewhen designing convectors.

FIG. 29 shows a conceptual three-dimensional model of a group offluid-cooled convectors 29C, driven by a single motor 29F. Connected inseries with the help of flexible couplers 29E, the convectors 29C,provide cooling to a group of microprocessors 29B that are mounted to aPC board 29A and held under some even pressure against the convectorswith the help of some retaining mechanism 29D. As the rotors within theconvectors spin with help from the external motor 29F, they draw freshfluid 29G from the outside, through a lateral intake 29H. After thefluid has picked up the heat from the internal plates, heat and air 29 iget expelled through an exhaust port 29J. An advantage of this kind ofset up is that the exhaust from all the individual convectors can bedirected to a single exhaust pipe, and the pipe can be directed to anarea away from the processors to avoid exhaust recirculation. Otheradvantages of this type of system is that it eliminates or reduces theuse of fans, eliminates or reduces the noise levels, they are compact,and because they are efficient, they reduce the amount of power neededto operate them and the convectors can utilize compressive ornon-compressive fluids.

Although FIG. 30 provides a sample of designs possible for basesutilized in convectors, this does not limit other designs not includedhere, but in general, all bases are made of highly thermal conductivematerials, have multiple channels for attachment of plates or fins thatare usually brazed, bonded or mechanically held in place, and becausebases are intended to transfer heat from a component or a device placedagainst them, they have their bottom surfaces to be machined andpolished to very small tolerances (±0.0005 inches [˜13 micrometers]) toimprove heat transfer. Bases can be utilized in conjunction with heatpipes and vapor chambers in order to provide better and efficient heattransfer capabilities.

Flat plates or fins for convectors come in many shapes, configurationsand sizes, FIG. 31 presents, but does not limit, designs of several finor stator plates where plates with multiple, radial openings near thecenter are plates utilized on convectors build around a solid shaft.Discs with a single, circular opening are utilized along hollow-tubularshafts.

Fin or stator plates do not have to be flat components. They can alsohave features to help contain the fluid as it spins between theirsurfaces or to strengthen the overall assembly. FIG. 32 presents, butdoes not limit, designs of several fins or stator plats build withseveral features such as a central clearance opening 32A, and flatindented areas 32B and bosses 32C to help contain and delimit therotating discs. Depending upon the design, this type of design canpractically eliminate the need of a casing for some convectors.

FIG. 33 presents a device built with three dimensional stator plates33A. As stated several times before, the purpose of fin separators is tocreate a cylindrical cavity for the spinning discs. The cavity helpscreate a chamber 33B that gives all fluid propulsing devices, such asconvectors, the ability to behave as pumps or as blowers with exhaustports tangential to the outer diameter of their chambers 33C. As it isshown in the exploded view of the device FIG. 34, the front cover 34C,the back cover 34D and all of the fins 34A that conform the stator 34Bhave features like bosses and indentations that prevent the use of finspacers. The back cover 34D clearly shows the scroll shape of the innerchamber of the device.

Convectors are by design, fluid propulsors like pumps and blowers. Theirperformance as such depends on a technical characteristic that must bepresent in every design: the scroll-shape (σ) of the chamber where thediscs rotate. FIG. 35 shows various convectors each of which has anexternal feature that makes the design different from the rest. Forexample, convector 35A has a straight plume exhaust, convector 35B has aflared plume exhaust, convector 35C has a narrow, plume-less exhaust,convector 35D has a narrow plume exhaust and convector 35E has nocasing, exposing a multiple set of plume-less exhaust openings. Thecross-sections of convectors 35A and 35B are shown in FIG. 36 todemonstrate the common denominator between these two convectors. So,while the convector on the left side of the drawing has a straight plumeexhaust 36D, the convector on the right has a flared plume exhaust, butall of the remaining characteristics are in both devices, exactly thesame. These characteristics include: 1) a chamber design 36A that wrapsthe disc early in its development and slowly increases in diameter; thisdesign characteristic is purposely added to devices whenever themovement of large fluid volume is required; devices with this featureare referred as volume convectors; as a result, convectors 35A and 35Bfall under this category; b) inclusion of fin separators or built-instructures to act as fin separators 36C; and c) disc diameter 36B is thesame for both devices.

The cross-sectional views of three convectors shown in FIG. 35 labeled35C, 35D and 35E are shown in FIG. 37 to demonstrate the commondenominator between these convectors. So, while the convector on theleft side of the drawing has a straight and narrow plume-less exhaust37D, the convector in the middle has a straight, narrow plume exhaustand the convector on the right side of the drawing has a narrow,plume-less exhaust on a device that has no casing. But, regardless ofthe differences described, the remaining characteristics in all of thedevices are exactly the same. These characteristics include: 1) achamber design 37A that wraps the disc completely, but with a narrow gapbetween the edge of the discs and the inner diameter of the chamber 37C;this design characteristic is purposely added to devices whenever theamount of pressure needed from the device is large; devices with thisfeature are referred as pressure convectors; convectors; as a result,convector 35C, 35D and 35E fall under this category; b) inclusion of finseparators or built-in structures to act as fin separators 37B; and c)disc diameter 37A is the same for all of the devices.

What is claimed is:
 1. A convector for cooling a microprocessor mountedto a CPU board of a computing device, the convector comprising: avolute-shaped housing mounted to the CPU board and thermally coupled tothe microprocessor, the volute-shaped housing having a radially outercasing defining a single exit port for guiding a fluid out of thehousing; a stator having a plurality of plates disposed inside theradially outer casing of the housing and configured to conduct heat; anda rotor having a shaft and plurality of disks, the shaft extendinglongitudinally along an axis from a front end of the housing to a rearend of the housing, wherein each of the plurality of disks is disposedinside the radially outer casing, adjacent at least a respective one ofthe plurality of plates of the stator, and rotatable with the shaftabout the axis, wherein the housing completely encapsulates the statorand the rotor, and wherein the housing, the stator, and the rotortogether define a spiral flow path through the volute-shaped housing, inboth radially outward and longitudinal directions, to the single exitport.
 2. The convector of claim 1, further comprising: a motormechanically coupled to the shaft of the convector for rotating theplurality of disks about the axis to drive the fluid along the spiralflow path.
 3. The convector of claim 1, further comprising: a retainingmechanism configured to hold the convector against the microprocessor.4. The convector of claim 3, wherein the retaining mechanism mounts theconvector to the CPU board above the microprocessor.
 5. The convector ofclaim 1, further comprising: a lateral intake for drawing the fluid fromoutside the housing into the housing.
 6. The convector of claim 1,wherein the shaft is hollow and defines an internal channel along theaxis of rotation and a plurality of radially outer apertures disposedalong and fluidly coupled to the internal channel.
 7. The convector ofclaim 6, wherein the plurality of radially outer apertures increase insize from one end of the hollow shaft to a central portion of the hollowshaft.
 8. The convector of claim 7, wherein each of the plurality ofdisks is disposed adjacent a respective one of the plurality of radiallyouter apertures.
 9. The convector of claim 8, wherein the housingdefines an inlet at a first end of the hollow shaft fluidly coupled withthe internal channel for guiding the fluid into the internal channel,along the axis, and through the plurality of radially outer apertures,and wherein a spiral flow path is defined by the housing, the stator,and the rotor from each radially outer aperture of the hollow shaft tothe single exit port for guiding the fluid from each radially outeraperture in both radially outward and longitudinal directions, to thesingle exit port.
 10. A convector according to claim 7, wherein thehousing further comprises a front plate at the front end, a rear plateat the rear end, and a base plate at a bottom end thereof, wherein theradially outer casing is coupled to the front plate, the rear plate, andthe base plate, wherein the hollow shaft extends through a frontaperture defined by the front plate and a rear aperture defined by therear plate, and wherein the front aperture of the front plate definesthe inlet at the first end of the hollow shaft, the rear plate definesan additional inlet at a second end of the hollow shaft opposite thefirst end, and the plurality of radially outer apertures also increasein size from the second end of the hollow shaft to the central portionof the hollow shaft.
 11. A convector according to claim 10, wherein thefront and rear plates are detachably coupled to the radially outercasing, and the base plate of the housing defines a concave region on atop side thereof configured to mechanically and thermally couple to theplurality of plates, and to receive and allow clearance for rotation ofthe plurality of disks.
 12. A convector according to claim 11, whereinthe base plate of the housing defines a flat bottom surface on a bottomside thereof for mounting the convector directly in contact with anexternal heated surface of the microprocessor.
 13. A convector accordingto claim 10, further comprising: a holding bar for connecting the frontplate, the radially outer casing, and the rear plate of the housing,wherein the radially outer casing has an outer rib defining an internalchannel configured to slidably receive the holding bar.
 14. A convectoraccording to claim 13, wherein the front plate and the rear plate eachhave a side tab configured to align with the internal channel of theouter rib, and the holding bar is configured to mechanically couple tothe front plate and the rear plate when slidably disposed within theinternal channel of the outer rib of the radially outer casing of thehousing, and wherein the holding bar defines a plurality of slotsconfigured to receive the plurality of plates.
 15. A convector accordingto claim 10, wherein each of the plurality of plates further comprises atop flange extending from a top end of the annular portion.
 16. Aconvector according to claim 6, wherein each of the plurality of platesof the stator comprises an annular portion defining a central openingthrough which the hollow shaft extends, and a bottom flange extendingdownward from a bottom end of the annular portion, and wherein thebottom flange is rectangular shaped and configured to mechanically andthermally couple to a base plate of the housing.
 17. A convectoraccording to claim 1, wherein each of the plates is volute-shaped, andcomprises a circular portion and a flange extending tangentially from anouter edge of the circular portion.
 18. A convector according to claim1, wherein the plurality of plates and the plurality of disks areinterleaved with respective surfaces thereof facing and offset from oneanother such that concurrent rotation of the plurality of disks forcesthe fluid along each spiral flow path to move toward the single exitport of the volute-shaped housing.
 19. A convector according to claim 1,wherein the single exit port includes a linear duct fluidly coupled withan opening in the radially outer casing of the housing, wherein thelinear duct has a width equal to a length of the housing between thefront and rear ends, and the radially outer casing is configured toguide different segments of the fluid, which reach the radially outercasing at respectively different longitudinal distances from the frontend of the housing, in a circumferential direction to varyinglongitudinal positions of the opening, and into the linear duct.
 20. Amicroprocessor cooling system for cooling an array of microprocessorsmounted to a CPU board of a computing device, the microprocessor coolingsystem comprising: a motor; and an array of mechanically coupledconvectors corresponding to the array of microprocessors, wherein eachconvector comprises: (i) a volute-shaped housing mounted to the CPUboard and held against a respective one of the array of microprocessors,the volute-shaped housing having a radially outer casing defining asingle exit port for guiding a fluid out of the housing; (ii) a statorhaving a plurality of plates disposed inside the radially outer casingof the housing and configured to conduct heat; and (iii) a rotor havinga hollow shaft mechanically coupled to the motor, and a plurality ofdisks, the hollow shaft extending longitudinally along an axis ofrotation from a front end of the housing to a rear end of the housing,and defining an internal channel and a plurality of radially outerapertures disposed along and fluidly coupled to the internal channel forguiding the fluid into the volute-shaped housing between a respectiveone of the plurality of plates and a respective one of the plurality ofdisks.